diff --git a/application/basilisk/base/content/browser-menubar.inc b/application/basilisk/base/content/browser-menubar.inc
index d4fd4d4c79..fbfddb56a8 100644
--- a/application/basilisk/base/content/browser-menubar.inc
+++ b/application/basilisk/base/content/browser-menubar.inc
@@ -5,7 +5,11 @@
 
        <menubar id="main-menubar"
                 onpopupshowing="if (event.target.parentNode.parentNode == this &amp;&amp;
+#ifdef MOZ_WIDGET_GTK
+                                    document.documentElement.getAttribute('shellshowingmenubar') != 'true')
+#else
                                     !('@mozilla.org/widget/nativemenuservice;1' in Cc))
+#endif
                                   this.setAttribute('openedwithkey',
                                                     event.target.parentNode.openedWithKey);"
                 style="border:0px;padding:0px;margin:0px;-moz-appearance:none">
diff --git a/application/basilisk/base/content/browser.js b/application/basilisk/base/content/browser.js
index ceca570a3b..49371b6240 100644
--- a/application/basilisk/base/content/browser.js
+++ b/application/basilisk/base/content/browser.js
@@ -4803,6 +4803,10 @@ function getTogglableToolbars() {
   let toolbarNodes = Array.slice(gNavToolbox.childNodes);
   toolbarNodes = toolbarNodes.concat(gNavToolbox.externalToolbars);
   toolbarNodes = toolbarNodes.filter(node => node.getAttribute("toolbarname"));
+#ifdef MOZ_WIDGET_GTK
+  if (document.documentElement.getAttribute("shellshowingmenubar") == "true")
+    toolbarNodes = toolbarNodes.filter(node => node.id != "toolbar-menubar");
+#endif
   return toolbarNodes;
 }
 
diff --git a/application/basilisk/base/content/tab-content.js b/application/basilisk/base/content/tab-content.js
index 1fdf42c9e5..af82f32ccd 100644
--- a/application/basilisk/base/content/tab-content.js
+++ b/application/basilisk/base/content/tab-content.js
@@ -892,11 +892,13 @@ UserContextIdNotifier.init();
 
 #ifdef MOZ_WEBEXTENSIONS
 ExtensionContent.init(this);
+#endif
 addEventListener("unload", () => {
+#ifdef MOZ_WEBEXTENSIONS
   ExtensionContent.uninit(this);
+#endif
   RefreshBlocker.uninit();
 });
-#endif
 
 addMessageListener("AllowScriptsToClose", () => {
   content.QueryInterface(Ci.nsIInterfaceRequestor)
diff --git a/application/basilisk/components/places/content/places.xul b/application/basilisk/components/places/content/places.xul
index 16c3385cbf..6d2cdf1712 100644
--- a/application/basilisk/components/places/content/places.xul
+++ b/application/basilisk/components/places/content/places.xul
@@ -156,8 +156,12 @@
 #ifdef XP_MACOSX
         <toolbarbutton type="menu" class="tabbable"
               onpopupshowing="document.getElementById('placeContent').focus()"
+#else
+#ifdef MOZ_WIDGET_GTK
+      <menubar id="placesMenu" _moz-menubarkeeplocal="true">
 #else
       <menubar id="placesMenu">
+#endif
         <menu accesskey="&organize.accesskey;" class="menu-iconic"
 #endif
               id="organizeButton" label="&organize.label;"
diff --git a/js/src/vm/NativeObject.h b/js/src/vm/NativeObject.h
index 3a3e50244f..e9c59ff7cd 100644
--- a/js/src/vm/NativeObject.h
+++ b/js/src/vm/NativeObject.h
@@ -646,7 +646,10 @@ class NativeObject : public ShapedObject
     uint32_t slotSpan() const {
         if (inDictionaryMode())
             return lastProperty()->base()->slotSpan();
-        return lastProperty()->slotSpan();
+
+        // Get the class from the object group rather than the base shape to avoid a
+        // race between Shape::ensureOwnBaseShape and background sweeping.
+        return lastProperty()->slotSpan(getClass());
     }
 
     /* Whether a slot is at a fixed offset from this object. */
diff --git a/netwerk/base/nsStandardURL.cpp b/netwerk/base/nsStandardURL.cpp
index 81b4855028..1866c10379 100644
--- a/netwerk/base/nsStandardURL.cpp
+++ b/netwerk/base/nsStandardURL.cpp
@@ -2747,12 +2747,16 @@ nsStandardURL::SetFilePath(const nsACString &input)
 
         return SetSpec(spec);
     }
-    else if (mPath.mLen > 1) {
+
+    if (mPath.mLen > 1) {
         mSpec.Cut(mPath.mPos + 1, mFilepath.mLen - 1);
         // left shift query, and ref
         ShiftFromQuery(1 - mFilepath.mLen);
+        // One character for '/', and if we have a query or ref we add their
+        // length and one extra for each '?' or '#' characters
+        mPath.mLen = 1 + (mQuery.mLen >= 0 ? (mQuery.mLen + 1) : 0) +
+                     (mRef.mLen >= 0 ? (mRef.mLen + 1) : 0);
         // these contain only a '/'
-        mPath.mLen = 1;
         mDirectory.mLen = 1;
         mFilepath.mLen = 1;
         // these are no longer defined